POSTSURGERY EPIDURAL BLOCKADE WITH LOCAL-ANESTHETICS ATTENUATES THE CATECHOLAMINE AND THERMOGENIC RESPONSE TO PERIOPERATIVE HYPOTHERMIA

Core (aural canal) and mean skin (15 sites) temperatures, plasma adren aline, noradrenaline and metabolites, and gaseous exchange were measur ed before, during and for 4 h after surgery in sixteen patients schedu led for elective colorectal surgery. All patients received general ana esthesia and no measures were taken to prevent the perioperative loss of body heat. At time of abdominal wall closure, when the core tempera ture was below 35.0 degrees C, the patients were randomly allocated to receive either 20-30 mg of papaveretum i.v. (papaveretum group, n=8 o r 15 ml of bupivacaine 0.75% via thoracic (T9) epidural route to obtai n a T4-S5 sensory blockade epidural group, n=8). Continuous infusion o f either i.v. papaveretum or epidural 0.25% bupivacaine was continued after surgery. During the recovery period of four hours the rate of in crease in core and mean skin temperatures was significantly slower in the epidural group compared with the papaveretum group (P<0.01). Plasm a catecholamine concentrations remained elevated after surgery in the papaveretum group, whilst they decreased significantly once epidural b lockade was established (P<0.001). There was a lower trend, however no t significant, in the rise of postoperative oxygen consumption and pla sma glucose concentration in the epidural group compared with the papa veretum group.